Variable venturi eor suction feed systems



' June 26, 1923. 1,459,961

, H. WHEELER I VARIABLE VENTURI FOR SUCTION FEED SYSTEMS Filed April 141922 -\3 I f 20 g ///////////A h M! &i$ i

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Patented June 26, 19.2.3.

UNITED STATE;

LEONARD H. WHEELER, OF CHICAGO, ILLINOIS, ASSIG-NOR TO STEWART-WARNERSPEEDOMETER COEPOEATION, VIRGINIA.

0F CHICAGO,

ILLINOIS, A CORPORATION OF VARIABLE VENTURE FOR SUCTION FEED SYSTEMS.

Application filed April 14:, 1922.

To all whom it may concern:

Be it known that I, Lnonnnn H. VJHEELER, a citizen of theUnited States,residing in the city of Chicago, in the county of Cook and State ofIllinois, have invented certain new and useful Improvements in VariableVenturi for Suction Feed Systems, of which the following is aspecification, reference being had to the accompanying drawings, forminga part thereof.

This invention relates to liquid feedingv apparatus of the type commonlyknown as the vacuum feet, and its purpose is to provide a constructionassociated with the exhaust pipe or conduit of an engine for utilizingthe flow of the exhaust to produce suction or vacuum for operating thefeed device. It consists of certain features of construction hereinafterdescribed and shown in the drawings, as indicated by the claims.

In the drawings Figure 1 is a diagrammatic side elevation of a liquidfeed system applied to an engine having a suction producing device inthe exhaust pipe constructed in accordance with this invention.

Figure 2 is a vertical axial section of the suction producing deviceitself.

Figure 3 is a transverse section taken as indicated at line, 3-3, onFigure 2.

The liquid feed system shown in the drawings comprises the usual lowlevel supply tank, A, which, as illustrated, may be understood as thefuel supply tank for an internal combustion engine shown at B, andhaving the carbureter, C, to which the fuel is fed by a vacuum feedtank, D, of well understood construction. such as that shown in JayPatent No. 1,125,519, dated January 19, 1915. As commonly installed. atthe present time, such a vacuum feed device depends for its suction uponthe partial vacuum produced in the intake manifold of the engine.However the suction is derived, the apparatus must include a suctionline or pipe, 1, a liquid supply pipe, 2, leading from the low leveltank, A, to the vacuum tank, D, and a feed pipe, 3, leading from thetank, D, to the carbureter, C. i

The engine exhaust manifold is indicated at 4, connected with an exhaustpipe, 5, and the suction producing device embodying this invention isshown as a fitting, 6, interposed Serial No. 552,806.

between the manifold, 1-, and the exhaust discharge passage, 5. Thefitting is shown as a metallic box of rectangular cross section having achamber, 7, formed'with parallel side walls, 8, 8, and a straight bottomwall, 9. The top wall of the chamber, 7, includes longitudinally andoppositely inclined portions, 10 and 11, and between the side walls, 8,there is mounted a movable partition, 12, having oppositely inclinedportions, 13 and 1 1, respectively, Said partition, 12, is preferablyrendered movable by a hinged or pivotal mounting, 15, at one end, and isformed at the other end with a stop lip, 16. which rests upon the bottomwall, 9, of the fitting, 6, at one limit of adjustment of the partition,12.

The partition, 12, co-operates with the inclined faces, 10 and 11, toform a Venturi passage for the exhaust gas from the engine, B, theportions, 10 and 13, and side walls, 8, defining the narrowing part ofthe passage while the surfaces, 11 and 14:, cooperate with the sidewalls to form the divergent or expanding section. At any convenientposition a spring, 17, is mounted to react between the partition, 12,and the bottom wall, 9, being preferably provided with a guide pin, 18,accommodated for movement through an opening, 19, in said wall. 9. Thetop wall of the fitting, 6, is formed with a suction port, 20,counterbored and tapped at 21, for connection with the suction pipe, 1,leading to the vacuum tank, D, and for convenience of mounting thefitting in the exhaust passage, it may be formed with end flanges, 22and 23, as shown.

The flow of exhaust gas through the Venturi throat formed by theconverging surfaces, 10 and 13. and the diverging surfaces, 11 and 14,will thus produce a suction which is of maximum value substantially atthe point of greatest constriction of the venturi indicated at 2 1. andthe vacuum tank, D, communicating with this constricted part, 2 1,through the pipe, 1, and port, 20, will thus be operated to lift liquidfrom the tank, A, and discharge it through the feed pipe, 3, in a wellunderstood manner.

It is desirable to maintain the value of the suction in the pipe, 1,fairly uniform, whereas the velocity and pressure of the exhaust gasesin the manifold, 4:, may vary with engine speed and other conditions.

As shown on Figure 2, the hinged parti tion, 12, is disposed at thelimit of its range which provides a maximum cross section for theconstriction, 24; but the spring, 17, will be made of such strength thatas the exhaust pressure in the manifold, 4, decreases, the spring willmove the partition, 12, toward the opposite wall and toward a limitindicated in dotted lines in Figure 2, for reducing the constriction,2 1. This adjustment by increasin the velocity of the exhaust at theconstrictlon, 24-, will tend to maintain a uniform suction at the port,20, and in the pipe, 1, as desired.

I claim:

1. In combination With an internal conibustion engine having an exhaustpassage and liquid fuel feeding means employing suction for moving thefuel for distribution to the engine, a suction producing devicecomprising a Venturi tube constituting a part of the engineexhaustpassage, and having an inlet leading to its constricted portionfrom the fuel feeding means for producing a suction effect thereon, saidVenturi tube being variable in shape for regulating such suction efiect.

2. In the combination defined in claim 1, said Venturi tube beingvariable in shape to modify the cross-sectional area of its constrictedportion.

3. In the combination defined in claim 2, yielding means tending tomaintain the shape of the venturi with said, cross-sectional area at aminimum, but adapted to yield automatically to an increase in pressureof the exhaust gas in the passage.

4. In combination with an internal combustion engine having an exhaustpassage and liquid fuel feeding means employing suction for moving thefuel for distribution to the engine, a suction-producing devicecomprising a Venturi tube constituting a part of the engine exhaustpassage, and having an inlet to its constricted portion lead-- I ingfrom said fuel feeding means for transmltting suction effect thereto,said Venturi tube being variable in shape for modifying said suctioneffect, and'means adapting the venturi to respond automatically tovariations in the exhaust pressure in the passage to maintain asubstantially uniform suction effect; i

5. 111 the combination defined in claim 1, said Venturi tube comprisingtwo fixed parallel Walls and a movable wall extending between themadjust-able transversely of the direction of flow of exhaust gas throughthe passage for modifying the cross-sectional area of the venturi.

6. In the combination defined in claim 5, yielding means tending to holdsaid movable wall in position to produce a minimum cross-sectional area.

7. In the combination defined in claim 5, said transversely movable wallhaving oppositely inclined portions extending respec tively in oppositedirections from the constricted part of the venturi,and a fixed wallopposing said movable wall with corresponding inc ined portions meetingat the constricted part of the venturi.

8. In the combination defined in claim 5, said movable wall being hingedat one end at a distance from the constricted part of the venturi forswinging both toward and from an opposite fixed wall.

9. In the combination defined in claim 8, said hinged wall having atransversely extendin lip at the end remote from its hinge formec toengage the edge of the adjacent part of the exhaust passage throughoutthe range of movement of the hinged'wall.

10. In combination with an internal combustion engine having an exhaustpassage and liquid fuel feeding means operatedby suction, a.suction-producing device including a venturi inserted in the exhaustpassage and comprising a fitting of interiorly rectangular cross-sectionwith two parallel side walls and a fixed transverse wallihavingoppositely inclined portions which meet at the constricted part of theVenturi throat, together with a second transverse wall having oppositelyinclined portions corresponding to those of said fixed wall, and alsomeeting at the constricted art of the venturi, provided. with means orguiding said second wall for movement toward and from the fixed. wall,said wall being adapted to yield away from the fixed wall upon increaseof the pressure in. the exhaust passage, and an inlet leading to theconstricted part of said venturi from the fuel feeding means foroperating thelatter by suction. i

In testimony whereof, I have hereunto setmy hand at Chicago, Illinois,this "11th day of April, 1922.

LEONARD H. WHEELER.

